package com.sky.service.impl;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.sky.constant.MessageConstant;
import com.sky.constant.StatusConstant;
import com.sky.dto.DishDTO;
import com.sky.dto.DishPageQueryDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.exception.DeletionNotAllowedException;
import com.sky.mapper.DishFlavorMapper;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealDishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.result.PageResult;
import com.sky.service.DishService;
import com.sky.vo.DishVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.sky.entity.DishFlavor;

import java.util.ArrayList;
import java.util.List;

@Service
@Slf4j
public class DishServiceImpl implements DishService {
    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private DishFlavorMapper dishFlavorMapper;
    @Autowired
    private SetmealDishMapper setmealDishMapper;
    @Autowired
    private SetmealMapper setmealMapper;

    /**
     * 新增菜品和对应的口味
     *
     * @param dishDTO
     */
    @Transactional     //事务注解，保持原子性，要么全成功要么全失败。（因为菜品和口味是两张不同的数据表，涉及到了多个数据表的操作）
    public void saveWithFlavor(DishDTO dishDTO) {
        Dish dish = new Dish();
        BeanUtils.copyProperties(dishDTO, dish);
        //向菜品表插入1条数据
        dishMapper.insert(dish);//后绪步骤实现
//获取insert语句生成的主键值
        Long dishId = dish.getId();
        List<DishFlavor> flavors = dishDTO.getFlavors();
        if (flavors != null && flavors.size() > 0) {    //因为口味为空也是允许的，就不插入了
            flavors.forEach(dishFlavor -> {
                dishFlavor.setDishId(dishId);
            });
//向口味表插入n条数据
            dishFlavorMapper.insertBatch(flavors);//批量插入口味
        }
    }

    /**
     * 菜品分页查询
     *
     * @param dishPageQueryDTO
     * @return
     */
    public PageResult pageQuery(DishPageQueryDTO dishPageQueryDTO) {
        PageHelper.startPage(dishPageQueryDTO.getPage(), dishPageQueryDTO.getPageSize());
        Page<DishVO> page = dishMapper.pageQuery(dishPageQueryDTO);//最左边那个Page是PageHelper插件的Page，别导错包了
        return new PageResult(page.getTotal(), page.getResult());
    }

    /**
     * 菜品批量删除
     *
     * @param ids
     */
    @Transactional//事务，因为下面涉及到了多个表的操作
    public void deleteBatch(List<Long> ids) {
//判断当前菜品是否能够删除---是否存在起售中的菜品？？
            for (Long id : ids) {
                Dish dish = dishMapper.getById(id);
                if (dish.getStatus() == StatusConstant.ENABLE) {
//则说明当前菜品处于起售中，不能删除。此时直接抛出异常就行
                    throw new DeletionNotAllowedException(MessageConstant.DISH_ON_SALE); //括号里就是一个提示信息，会展示到前端
                }
            }
//判断当前菜品是否能够删除---是否被套餐关联了？？
            List<Long> setmealIds = setmealDishMapper.getSetmealIdsByDishIds(ids);
            if (setmealIds != null && setmealIds.size() > 0) {
//当前菜品被套餐关联了，不能删除
                throw new DeletionNotAllowedException(MessageConstant.DISH_BE_RELATED_BY_SETMEAL);
            }
//删除菜品表中的菜品数据和口味数据
            /*for (Long id : ids) {
                dishMapper.deleteById(id);
                dishFlavorMapper.deleteByDishId(id);
            }*/
//        上面这段代码有时要集合里的菜品太多，而一次遍历就需要两次sql语句，性能不好，所以换成下面的：无论要删除的菜品有多少个，执行的sql语句次数都只是那2次
//        根据菜品id集合批量删除菜品数据。sql：delete from dish where id in (?,?,?)
        dishMapper.deleteByIds(ids);
//        根据菜品id集合批量删除菜品数据。sql：delete from dish_flavor where dish_id in (?,?,?)
        dishFlavorMapper.deleteByDishIds(ids);
        }

    /**
     * 根据id查询菜品和对应的口味数据
     *
     * @param id
     * @return
     */
    public DishVO getByIdWithFlavor(Long id) {
//根据id查询菜品数据
        Dish dish = dishMapper.getById(id);
//根据菜品id查询口味
        List<DishFlavor> dishFlavors = dishFlavorMapper.getByDishId(id);
//将上面查询到的两部分一起封装到VO
        DishVO dishVO = new DishVO();
        BeanUtils.copyProperties(dish, dishVO);
        dishVO.setFlavors(dishFlavors);
        return dishVO;
    }

    /**
     * 根据id修改菜品基本信息和对应的口味信息
     *
     * @param dishDTO
     */
    public void updateWithFlavor(DishDTO dishDTO) {
        Dish dish = new Dish();
        BeanUtils.copyProperties(dishDTO, dish);
//修改菜品表基本信息
        dishMapper.update(dish);
        //删除原有的口味数据，因为这个口味操作比较复杂，你自己去前端看看，用户修改口味的时候，可能是删除，换新的，也可能是直接再加个新的。所以用下面代码：统一删掉旧口味，再插入新的
        dishFlavorMapper.deleteByDishId(dishDTO.getId());
//重新插入口味数据
        List<DishFlavor> flavors = dishDTO.getFlavors();
        if (flavors != null && flavors.size() > 0) {
            flavors.forEach(dishFlavor -> {
                dishFlavor.setDishId(dishDTO.getId());
            });
//向口味表插入n条数据
            dishFlavorMapper.insertBatch(flavors);
        }
    }

    /**
     * 菜品起售停售
     *
     * @param status
     * @param id
     */
    @Transactional
    public void startOrStop(Integer status, Long id) {
        Dish dish = Dish.builder()
                .id(id)
                .status(status)
                .build();
        dishMapper.update(dish);
        if (status == StatusConstant.DISABLE) {
// 如果是停售操作，还需要将包含当前菜品的套餐也停售
            List<Long> dishIds = new ArrayList<>();
            dishIds.add(id);
// select setmeal_id from setmeal_dish where dish_id in (?,?,?)
            List<Long> setmealIds = setmealDishMapper.getSetmealIdsByDishIds(dishIds);
            if (setmealIds != null && setmealIds.size() > 0) {
                for (Long setmealId : setmealIds) {
                    Setmeal setmeal = Setmeal.builder()
                            .id(setmealId)
                            .status(StatusConstant.DISABLE)
                            .build();
                    setmealMapper.update(setmeal);
                }
            }
        }
    }

    /**
     * 根据分类id查询菜品
     * @param categoryId
     * @return
     */
    public List<Dish> list(Long categoryId) {
        Dish dish = Dish.builder()
                .categoryId(categoryId)
                .status(StatusConstant.ENABLE)
                .build();
        return dishMapper.list(dish);
    }

    /**
     * 条件查询菜品和口味
     * @param dish
     * @return
     */
    public List<DishVO> listWithFlavor(Dish dish) {
        List<Dish> dishList = dishMapper.list(dish);

        List<DishVO> dishVOList = new ArrayList<>();

        for (Dish d : dishList) {
            DishVO dishVO = new DishVO();
            BeanUtils.copyProperties(d,dishVO);

            //根据菜品id查询对应的口味
            List<DishFlavor> flavors = dishFlavorMapper.getByDishId(d.getId());

            dishVO.setFlavors(flavors);
            dishVOList.add(dishVO);
        }

        return dishVOList;
    }

    }
